Removal of Chromium (VI) in Tannery Wastewater by Immobilized Technology

Abstract

Bacillus cereus was embedded in powdered activated carbon to prepare immobilized granule. Then, the granules was used to treat the Cr(VI) in tannery wastewater. The results showed the removal effect of Cr(VI) removed by the immobilized Bacillus cereus was better than either the single powdered activated carbon or the single Bacillus cereus. SEM photograph showed that the Bacillus cereus in the granules grew well. After the total chromium and the Cr(VI) in the solution and the granules were detected before and after treatment, it was found that the Cr(VI) in the solution and the granules was decreased, but the total chromium was changeless, which indicated that the removal of Cr(VI) with the granules was mainly as the results of both the chromate reductase produced by Bacillus cereus and the adsorption of activated carbon. The kinetics data of Cr(VI) removed by immobilized Bacillus cereus could be well-described by pseudo-second-order rate model. The experiments demonstrated that the immobilized Bacillus cereus could be selected as a new biomaterial to remove Cr(VI) in tannery wastewater.